Bomb technicians are currently clearing a house in Escondido, California containing the largest cache of certain homemade explosives ever found in the U.S. Among other weapons, the stash includes 9 pounds of suicide bomber-favorite HMTD.

The explosives were discovered last week after a gardener accidentally ignited some of the hexamethylene triperoxide diamine (HMTD) powder, causing the explosion is shown in the image above. In addition to the HMTD, grenades, and other weapons, authorities believe the house could contain pentaerythritol tetranitrate or PETN, an explosive used by the shoe bomber Richard Reid in 2001. San Diego County sheriff's officials described the home as "very cluttered" with "no free space."

The owner of the home is 54-year-old George Djura Jakubec, a naturalized U.S. citizen from Serbia. Jakubec's currently being held on $5 million bail after pleading not guilty to 28 felonies charges: 13 counts of possession of a destructive device, 13 counts of possession of ingredients to make a destructive device and two robbery charges stemming from earlier incidents at banks. The two residences immediately adjacent to Jakubec's home have been evacuated while the bomb technicians complete their sweep. [CNN and 10 News]